In the construction of a home or building, it is usual practice to provide a T-fitting wherever a fixture of the type having a trap is to be located. The T-fitting comprises a part of a soil pipe and vent pipe assembly as is well-known in the art. The trap of the fixture is normally connected to the center port of the T-fitting. In the case of a lavatory or the like, this connection is made through an appropriate hole in the wall behind which the T-fitting is located and in front of which the lavatory is mounted.
In the pumbing industry today, it is common to make piping such as soil pipe and vent pipe, and fittings such as T-fittings, traps, and the like out of plastic material. The most commonly used plastic material for such applications is acrylonitrile-butadiene-styrene (ABS) or polyvinylchloride (PVC). The present invention is directed to plastic piping and fittings.
In a typical 21/2 bath home there will probably be 10 or more T-fittings for connection to the traps of one or more lavatories, one or more showers, one or more bathtubs, a kitchen sink, a washing machine drain, and the like.
During construction, the basic plumbing is generally installed, quite some time before the installation of the various fixtures. As a consequence, the intermediate ports of the T-fittings will not have traps connected thereto for some time. It is therefore desireable to close and seal the intermediate ports of the T-fittings for several reasons. First of all, it helps prevent clogging of the basic plumbing with dirt and foreign material which might inadvertently enter these intermediate ports during construction. Furthermore, during plumbing construction it is frequently desireable or required to perform an air test or a water test to assure that the various joints are properly connected and fluid-tight.
The closing and sealing of the intermediate ports of the T-fittings has been accomplished by the prior art in a number of different ways. One common approach is to insert a length of pipe through the hole in the wall and into the intermediate port of the T-fitting, permanently adhering the pipe to the intermediate port by gluing, solvent welding, or the like. This provides a fluid-tight connection. The free end of the pipe is then closed by a wafer cap. The wafer cap comprises a relatively thin plastic cap, solvent welded or otherwise sealingly affixed to the free end of the pipe. The necessary cleaning and welding steps are time consuming. Furthermore, while the air or water tests are performed at relatively low pressures, the wafer caps are characterized by a failure rate of from about 30% to about 35%.
Another prior art approach is to apply to the end of the pipe attached to the center port of the T-fitting, a resilient rubber cap held in place by a hose clamp. Unlike the wafer cap, this type of closure has the advantage of being reusable. Nevertheless, its installation is time consuming, it is frequently lost or misplaced, and it, too, demonstrates a relatively high failure rate.
Most basic plumbing of the type to which the present invention is directed is accomplished with so-called "schedule 40" pipe and pipe fittings. Pipe and fittings of this type are conventional, readily available and well-known in the art. The term "schedule 40" refers to the thickness or gauge of the pipe wall.
Yet another approach by prior art workers is to close the free end of the pipe, extending from the center port of the T-fitting through the wall, by a schedule 40 cap. This is a relatively heavy-duty cap structure which is glued or solvent welded to the free end of the pipe. The cap is expensive and constitutes a single use item.
The present invention relates to a fitting for closing and sealing the intermediate port of the T-fitting while overcoming the problems associated with the various prior art devices for this purpose. Once installed, the fitting of the present invention will easily withstand a head of water or a water test or air test. In addition to this, the fitting can be cut substantially flush with the wall and will serve as a bushing for both tubular and schedule 40 traps. That portion of the fitting which was cut off can be used again. This is true until the length of the fitting is substantially consumed. The fitting is characterized by excellent strength, since its wall thickness is greater than that of schedule 40 pipe and fittings. The device of the present invention is easy and inexpensive to manfacture. Use of the fitting requires less time and fewer manipulative steps. The fitting of the present invention eliminates the necessity for a trap adapter. Prior to trap installation, the test and trap fitting of the present invention provides a closing and sealing device for the intermediate port of the T-fitting which is both reliable and safe.